JP2017132874A - Earth label for adhering electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earth label for adhering an electronic component having high adhesive force, excellent in conductivity, further high in inhibition effect of oxidation deterioration of an adherend, good in printing and printability and applicable even to hard disc drive (HDD) or the like.SOLUTION: There is provided an earth label for adhering an electronic component by laminating an adhesive layer formed from an adhesive composition containing an adhesive resin and a carbon-based filler with average aspect ratio of 3.0 or more of 0.01 to 20 mass% and having acid value of 5.0 mgKOH/g or less and a detachment sheet on a substrate in this order, which has silicon atom concentration to total 100 atom% of each atom concentration of carbon atom, oxygen atom and silicon atom measured by an X-ray photoelectric spectrometry (XPS) of less than 0.5 atom% respectively in each layer constituting the earth label.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an earth label for attaching an electronic component.

Conventionally, conductive earth labels for attaching electronic components have been used for applications such as electromagnetic shielding materials for electronic devices such as computers and communication devices and containers for storage, ground wires for electrical components, and sparks caused by static electricity. It is used. Such an earth label for attaching electronic parts is used not only for fixing components and displaying contents, but also for providing antistatic performance, such as a hard disk drive (HDD), a relay, various switches, connectors, and the like. It is also used for devices such as motors.
As a specific configuration of the earth label for attaching electronic parts, a metal such as copper powder, silver powder, nickel powder, aluminum powder, etc. is used to impart antistatic property and conductivity to the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition. A configuration in which a conductive substance such as powder is dispersed is employed.

Various types of such ground labels for attaching electronic parts have been proposed.
For example, in Patent Document 1, a mesh-like metal vapor deposition film is provided on one surface of a resin film, and an average particle size of 100 mesh is applied to 100 parts by mass of acrylic adhesive (solid content of 40 parts by mass) on the metal vapor deposition film. A conductive pressure-sensitive adhesive tape having a conductive pressure-sensitive adhesive layer formed from a conductive pressure-sensitive adhesive containing about 50 parts by mass of copper powder (average particle size of about 150 μm) is disclosed.

Patent Document 2 discloses a conductive pressure-sensitive adhesive layer made of a conductive pressure-sensitive adhesive in which a conductive material selected from carbon nanotubes and / or carbon microcoils is dispersed in a pressure-sensitive adhesive on a conductive support layer. The provided conductive composite is disclosed.
Patent Document 2 has a description that an acrylic pressure-sensitive adhesive or a silicone pressure-sensitive adhesive is preferable as the pressure-sensitive adhesive in the conductive pressure-sensitive adhesive layer, and the type of the pressure-sensitive adhesive is not particularly limited.

JP-A-11-323275 JP 2001-172582 A

In order to obtain sufficient conductivity, the conductive pressure-sensitive adhesive tape described in Patent Document 1 needs to sufficiently contact the metal particles blended in the pressure-sensitive adhesive composition with the metal vapor deposition layer. To that end, Patent Document 1 attempts to improve conductivity by blending a large amount of metal particles with the adhesive, but tends to cause a decrease in adhesive force and holding power.
Furthermore, in the conductive adhesive tape described in Patent Document 1, the surface of the metal vapor-deposited layer may be oxidized to form an oxide film, and the formation of the oxide film not only reduces the adhesive force and conductivity. Further, there may be a problem in appearance that the color tone of the conductive adhesive tape changes.

In addition, the conductive composite material described in Patent Document 2 is supposed to be used as an electromagnetic wave shielding material or a leakage current removing material for electronic devices and parts. For example, a silicone-based pressure-sensitive adhesive is used as the pressure-sensitive adhesive. In such a case, it is not suitable for an application for attaching HDD parts.
That is, when a pressure-sensitive adhesive layer using a silicone-based pressure-sensitive adhesive is attached to an adherend, siloxane gas derived from the silicone-based compound in the silicone-based pressure-sensitive adhesive may be gradually generated. The generated siloxane gas forms a deposit made of a fine silicone compound on the surface of the electrical contact portion by, for example, an arc generated in the vicinity of the electrical contact portion of the electrical component. This deposit also causes the occurrence of poor electrical conductivity of electrical components. In particular, when the deposit accumulates on a magnetic head or a disk surface in the HDD, it becomes easy to cause reading or writing failure of the hard disk.

Furthermore, if a conventional earth label for attaching electronic components is attached to an adherend and left for a while in a high-temperature and high-humidity environment, the surface of the adherend to which the earth label is attached may be oxidized and deteriorated. It can also be a factor in reducing the reliability of equipment.
In addition, earth labels for attaching electronic parts are often used by printing or printing information such as the manufacturing number of parts to be adhered and electronic devices on the surface of the base material of the earth label. There is also a demand for printability.

  The present invention is an electronic that can be applied to a hard disk drive (HDD) or the like that has high adhesive strength, is excellent in electrical conductivity, has a high effect of suppressing oxidative deterioration of an adherend, and has good printability and printability. The purpose is to provide a grounding label for parts.

  As a material for forming the pressure-sensitive adhesive layer, the present inventors use a pressure-sensitive adhesive composition containing a predetermined amount of a carbon-based filler having a specific shape together with a pressure-sensitive resin, and adjusting the acid value. It has been found that an earth label for attaching an electronic component having a silicon atom concentration of a predetermined value or less can solve the above problems.

That is, the present invention relates to the following [1] to [5].
[1] From an adhesive composition containing 0.01 to 20% by mass of a carbon-based filler having an average aspect ratio of 3.0 or more and an acid value of 5.0 mgKOH / g or less together with an adhesive resin on a substrate. It is a ground label in which the formed adhesive layer and release sheet are laminated in order,
In each layer constituting the earth label, the silicon atom concentration is less than 0.5 atom% with respect to a total of 100 atom% of each atom concentration of carbon atom, oxygen atom, and silicon atom measured by X-ray photoelectric spectroscopy (XPS). An earth label for attaching electronic components.
[2] The above-mentioned pressure-sensitive adhesive resin contains an acrylic copolymer having a structural unit (a1) derived from alkyl (meth) acrylate and a structural unit (a2) derived from (meth) acryloylmorpholine. [1] A grounding label for attaching an electronic component according to [1].
[3] The ground label for attaching an electronic component according to the above [1] or [2], wherein the adhesive resin is an adhesive resin having no carboxy group.
[4] Any one of the above [1] to [3], wherein the substrate has a structure in which a coating layer for printing is further laminated on the surface opposite to the side on which the pressure-sensitive adhesive layer is laminated. A grounding label for attaching electronic components as described in 1.
[5] The ground label for attaching an electronic component according to any one of [1] to [4], which is used for attaching a component in a hard disk.

  The ground label for attaching electronic parts of the present invention has a high adhesive force, is excellent in electrical conductivity, has a high effect of suppressing oxidative deterioration of the adherend, is excellent in printability and printability, and is suitable for attaching parts in HDDs. Even if it uses, the fall of reliability can be avoided.

It is a cross-sectional schematic diagram which shows an example of the usage condition of the earth label for electronic component sticking of this invention.

In the following description, “mass average molecular weight (Mw)” is a value in terms of polystyrene measured by a gel permeation chromatography (GPC) method, and specifically measured based on the method described in the examples. Value.
For example, “(meth) acrylic acid” is used as a term indicating both “acrylic acid” and “methacrylic acid”, and the same applies to other similar terms.

[Earth labels for attaching electronic components]
The ground label for attaching electronic parts of the present invention (hereinafter also simply referred to as “earth label”) has a structure in which an adhesive layer and a release sheet are laminated on a base material.
In other words, the ground label for attaching an electronic component of the present invention only needs to have a configuration in which the base material / the adhesive layer / the release sheet are laminated in this order, for example, to improve the adhesion between the base material and the adhesive layer. Therefore, it is good also as a structure which provided the primer layer between the base material and the adhesive layer.
Further, as one aspect of the present invention, an earth label having a configuration in which a coating layer for printing is laminated on the surface of the base material opposite to the side on which the pressure-sensitive adhesive layer is laminated may be used.

FIG. 1 is a schematic cross-sectional view showing an example of a usage mode of the ground label for attaching an electronic component of the present invention.
In FIG. 1, the release sheet is removed from the ground label 1 of the present invention, and the surface of the exposed pressure-sensitive adhesive layer 12 spans both the electronic component 21 of the conductor to be grounded and the housing 22 to be grounded. In this manner, the mode of use is shown.
The pressure-sensitive adhesive layer 12 of the earth label 1 of the present invention is formed from a pressure-sensitive adhesive composition containing a carbon-based filler having an average aspect ratio of 3.0 or more. In the formed pressure-sensitive adhesive layer 12, a plurality of carbon-based fillers are dispersed by forming a network network.
The static electricity charged on the electronic component 21 to be grounded is discharged to the grounded housing 22 via the carbon filler network in the pressure-sensitive adhesive layer 12 to remove the static electricity charged on the electronic component 21. it can.

In the ground label 1 of the present invention, information such as the manufacturing number of the electronic component may be printed or printed on the surface 11a on the side opposite to the side on which the adhesive layer 12 of the substrate 11 is laminated. .
Moreover, when the ground label 1 of this invention is the structure which the coating layer for printing printing laminated | stacked on the surface 11a of the base material 11, it may be printed or printed on this coating layer for printing.

  In addition, the ground label of the present invention can easily adjust the surface of the pressure-sensitive adhesive layer that appears when the release sheet is removed, and can make the thickness substantially uniform. Printability can be improved.

Carbon atoms and oxygen atoms measured by X-ray photoelectric spectroscopy (XPS) in each layer (base material, pressure-sensitive adhesive layer, release sheet, primer layer, print printing coat layer, etc.) constituting the ground label of the present invention , And silicon atom concentration (hereinafter also referred to as “silicon atom concentration”) with respect to a total of 100 atom% of each atom concentration of silicon atoms is less than 0.5 atom%.
The silicon atom concentration in each layer indirectly indicates the content of the silicone compound contained in the target layer.
That is, it can be said that the layer having a high silicon atom concentration contains a large amount of the silicone compound.

As described above, when a silicone compound is contained in each layer constituting the ground label, after the siloxane gas derived from the silicone compound is gradually generated, the siloxane gas is minutely formed on the surface of the electrical contact portion. In some cases, a deposit composed of a silicone compound is formed.
This deposit also causes the occurrence of electrical conductivity failure of electrical components, and in particular, when it accumulates on the magnetic head in the HDD, the disk surface, etc., it also causes the read or write failure of the hard disk.
In the ground label of the present invention, in consideration of the above-mentioned problems, the silicon atom concentration in each layer constituting the ground label is less than 0.5 atom% in consideration of the case where it is used for affixing parts in HDDs. The content of the silicone compound is indirectly limited.

In the present invention, the term “silicone compound” means a compound having a siloxane bond (—Si—O—) in the molecule. For example, polydimethylsiloxane, polymethylphenylsiloxane, polymethylhydrogensiloxane, etc. Various modified silicones into which modified silicones, polyethers, epoxies, amines, carboxyl groups, aralkyl groups, fluorine-containing fluoroalkyl groups and the like are introduced may be mentioned.
These silicone compounds can also be a factor in the generation of siloxane gas.
In addition, the content of these silicone compounds can be indirectly calculated from the silicon atom concentration measured by XPS.

In each layer constituting the earth label of the present invention, the silicon atom concentration relative to the total atom concentration of carbon atoms, oxygen atoms, and silicon atoms measured by XPS is 100 atom% is less than 0.5 atom%, preferably It is less than 0.3 atom%, more preferably less than 0.2 atom%.
In the present specification, the silicon atom concentration is a value calculated from each atom concentration of carbon atom, oxygen atom, and silicon atom measured by XPS, and specifically, by the method described in the examples. Means the measured value.

Hereinafter, each configuration of the ground label of the present invention will be described.
<Base material>
As the base material, various materials can be used within the scope of the effects of the present invention, and are appropriately selected according to the intended use of the ground label of the present invention. For example, it may be a conductive substrate made of a conductive material such as metal, or may be an insulating substrate made of an insulating material.
The ground label of the present invention contains a carbon-based filler in the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer has excellent antistatic properties and conductivity. Therefore, even if an insulating substrate is used, the pressure-sensitive adhesive layer The antistatic property and electroconductivity outstanding with respect to this surface can be expressed.

Examples of the insulating base material include various types of paper such as fine paper, art paper, coated paper, glassine paper, and laminated paper obtained by laminating a thermoplastic resin such as polyethylene on these paper base materials; Material: Synthetic paper made of polyethylene resin, polypropylene resin, etc .; Polyolefin resin such as polyethylene resin, polypropylene resin, polyester resin such as polybutylene terephthalate resin, polyethylene terephthalate resin, acetate resin, ABS resin, polystyrene resin, vinyl chloride resin, etc. And a plastic film or sheet comprising a mixture of these resins; a plastic film or sheet comprising a laminate of these plastic films or sheets.
The base sheet such as a plastic film or sheet may be unstretched, or may be stretched in a uniaxial direction or a biaxial direction such as longitudinal or lateral.

Examples of the conductive substrate include metal foil, metal-deposited plastic film or sheet obtained by depositing metal on the above-described plastic film or sheet, metal fiber (non) woven fabric, metal-coated fiber (non) woven fabric, carbon fiber ( Non-) woven fabric and the like.
Moreover, as a metal which comprises the said electroconductive base material, single metal or 2 types, such as platinum, gold | metal | money, silver, copper, palladium, tungsten, aluminum, nickel, chromium, iron, magnesium, zinc, tin, for example The alloy which combined the above metals is mentioned.

As these base materials, a plastic film or sheet having a hard coat on the surface or a plastic film or sheet capable of printing or printing on the surface may be used, but printing or printing is possible on the surface. A plastic film or sheet is preferred.
The base material used in the present invention may further contain an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a slip agent, an antiblocking agent, a colorant and the like.

In addition, when the substrate is a plastic film or sheet, from the viewpoint of improving the adhesion between the substrate and the pressure-sensitive adhesive layer, a surface treatment such as an oxidation method or a concavo-convex method is performed on the surface of the substrate as necessary. It is preferable to apply.
The oxidation method is not particularly limited, and examples thereof include a corona discharge treatment method, a plasma treatment method, chromic acid oxidation (wet), flame treatment, hot air treatment, and ozone / ultraviolet irradiation treatment. Moreover, it does not specifically limit as an uneven | corrugated method, For example, a sandblasting method, a solvent processing method, etc. are mentioned. These surface treatments are appropriately selected according to the type of the substrate, but the corona discharge treatment method is preferred from the viewpoint of improving the adhesion with the pressure-sensitive adhesive layer and operability. Moreover, primer treatment can also be performed.

  Although the thickness of a base material is suitably adjusted according to a use etc., from a viewpoint of easy handling, Preferably it is 10-250 micrometers, More preferably, it is 15-200 micrometers, More preferably, it is 20-150 micrometers.

<Adhesive layer>
The pressure-sensitive adhesive layer of the earth label of the present invention contains 0.01 to 20% by mass of a carbon-based filler having an average aspect ratio of 3.0 or more and an adhesive having an acid value of 5.0 mgKOH / g or less together with the adhesive resin. It is formed from a sex composition.
Although the thickness of an adhesive layer is suitably adjusted according to a use etc., Preferably it is 0.5-100 micrometers, More preferably, it is 1-60 micrometers, More preferably, it is 3-40 micrometers.
When the thickness of the pressure-sensitive adhesive layer is 0.5 μm or more, good adhesive force can be obtained for the adherend. On the other hand, if the thickness of the pressure-sensitive adhesive layer is 100 μm or less, it is advantageous in terms of productivity, and an easy-to-handle ground label can be obtained.

The pressure-sensitive adhesive composition, which is a material for forming the pressure-sensitive adhesive layer, contains 0.01 to 20% by mass of a carbon-based filler having an average aspect ratio of 3.0 or more together with the pressure-sensitive resin, depending on the type of the pressure-sensitive resin. In addition, it is preferable to further include one or more selected from an oligomer component, a tackifier, and a crosslinking agent.
Moreover, the said adhesive composition may contain other additives other than the above in the range which does not impair the effect of this invention.

The total content of the adhesive resin and the carbon-based filler in the adhesive composition used in the present invention is preferably 60% by mass or more with respect to the total amount (100% by mass) of active ingredients in the adhesive composition. More preferably, it is 70 mass% or more, More preferably, it is 80 mass% or more, More preferably, it is 90 mass% or more.
In the present invention, the “active ingredient in the adhesive composition” means a component obtained by removing water or an organic solvent non-reactive solvent from the adhesive composition.

In the present invention, the acid value of the pressure-sensitive adhesive composition that is a material for forming the pressure-sensitive adhesive layer is 5.0 mgKOH / g or less, preferably 3.0 mgKOH / g or less, more preferably 1.0 mgKOH / g or less, Preferably it is 0.5 mgKOH / g or less, More preferably, it is 0.1 mgKOH / g or less.
When the acid value of the pressure-sensitive adhesive composition exceeds 5.0 mgKOH / g, the obtained earth label may cause the adherend to deteriorate the acid value. In other words, if such an earth label is affixed to an easily oxidizable adherend such as copper and left for a while in a high temperature and high humidity environment, the surface of the adherend to which the earth label is affixed may be oxidized and deteriorated. It can also be a factor in reducing the reliability of equipment. In addition, the pressure-sensitive adhesive layer may be discolored with the oxidation of the adherend, and there is a problem in discoloration resistance.
In addition, the acid value of the pressure-sensitive adhesive composition includes a pressure-sensitive adhesive resin and a carbon-based filler to be blended, an oligomer component, a tackifier, a crosslinking agent, and other additives other than these blended as necessary. It is the acid value of the adhesive composition which all included, and is the value measured by the method as described in an Example.

[Adhesive resin]
In the present invention, the adhesive resin means a resin having adhesiveness by itself and having a mass average molecular weight (Mw) of 10,000 or more.
The mass average molecular weight (Mw) of the adhesive resin is preferably 10,000 to from the viewpoint of easily forming an adhesive layer having a high occupation area ratio of the carbon-based filler (B) on the pasting surface. It is 2 million, More preferably, it is 20,000-1 million, More preferably, it is 30,000-1 million.

Examples of the adhesive resin used in one embodiment of the present invention include acrylic resins, urethane resins, polyisobutylene resins, polyester resins, and polyolefin resins.
These adhesive resins may be used alone or in combination of two or more.

Among these, the adhesive resin used in one embodiment of the present invention preferably includes an acrylic resin.
The content of the acrylic resin is preferably 30 to 100% by mass, more preferably 50 to 100% by mass, and still more preferably, with respect to the total amount (100% by mass) of the adhesive resin contained in the adhesive composition. It is 70-100 mass%, More preferably, it is 85-100 mass%.

  From the viewpoint of reducing the acid value of the adhesive composition, the adhesive resin used in one embodiment of the present invention is preferably an adhesive resin having no carboxy group, and an acrylic resin having no carboxy group. It is more preferable to contain a resin.

  The content of the adhesive resin in the adhesive composition is preferably from 30 to 99.99 mass%, more preferably from 40 to 99, based on the total amount (100 mass%) of the active ingredients in the adhesive composition. .95% by mass, more preferably 50 to 99.90% by mass, still more preferably 60 to 99.80% by mass, and still more preferably 70 to 99.50% by mass.

(Acrylic resin)
As an acrylic resin used in one embodiment of the present invention, for example, a polymer including a structural unit derived from an alkyl (meth) acrylate having a linear or branched alkyl group, or derived from a (meth) acrylate having a cyclic structure And a polymer containing the structural unit.
Further, when these polymers are copolymers, the form of copolymerization is not particularly limited, and examples of the acrylic copolymer include block copolymers, random copolymers, and graft copolymers. Either may be sufficient.

  The mass average molecular weight (Mw) of the acrylic resin is preferably 100,000 to 1,500,000, more preferably 200,000 to 1,300,000, still more preferably 350,000 to 1,100,000, still more preferably 500,000 to 900,000. .

The acrylic resin used in one embodiment of the present invention includes a structural unit (a1) derived from alkyl (meth) acrylate (a1 ′) (hereinafter also referred to as “monomer (a1 ′)”), and (meth) acryloylmorpholine. An acrylic copolymer having a structural unit (a2) derived from (hereinafter also referred to as “monomer (a2 ′)”) is preferable, and together with the structural units (a1) and (a2), a functional group-containing monomer (a3 An acrylic copolymer containing the structural unit (a3) derived from ') (hereinafter also referred to as "monomer (a3')") is more preferable.
In addition, you may use said monomer (a1 ')-(a3') individually or in combination of 2 or more types.
By using the acrylic copolymer having the structural unit (a2) as described above, it is possible to obtain an earth label with further improved adhesion and holding power.

The number of carbon atoms of the alkyl group contained in the monomer (a1 ′) is preferably 1 to 12, more preferably 4 to 8, and still more preferably 4 to 6, from the viewpoint of improving adhesive properties.
Examples of the monomer (a1 ′) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and tridecyl ( Examples include meth) acrylate and stearyl (meth) acrylate.
Among these monomers (a1 ′), butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are preferable, and butyl (meth) acrylate is more preferable.

  The content of the structural unit (a1) is preferably 50 to 99.5% by mass, more preferably 60 to 99% by mass, and still more preferably based on all the structural units (100% by mass) of the acrylic copolymer. Is 70 to 97 mass%, more preferably 80 to 95 mass%.

As the monomer (a2 ′), acryloylmorpholine is preferable.
The content of the structural unit (a2) is preferably 0.00 with respect to the total structural unit (100% by mass) of the acrylic copolymer from the viewpoint of providing an earth label with improved adhesion and holding power. It is 5-35 mass%, More preferably, it is 1.0-30 mass%, More preferably, it is 3.0-25 mass%, More preferably, it is 5.0-20 mass%.

Examples of the monomer (a3 ′) include hydroxy group-containing monomers, carboxy group-containing monomers, epoxy group-containing monomers, amino group-containing monomers, cyano group-containing monomers, and keto group-containing monomers.
In the present invention, (meth) acryloylmorpholine corresponds to the monomer (a2) and is excluded from the monomer (a3 ′).
Among these monomers (a3 ′), a hydroxy group-containing monomer is preferable.

  Examples of the hydroxy group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl ( Examples thereof include hydroxyalkyl (meth) acrylates such as meth) acrylate and 4-hydroxybutyl (meth) acrylate; unsaturated alcohols such as vinyl alcohol and allyl alcohol.

  The content of the structural unit (a3) is preferably 0.1 to 30% by weight, more preferably 0.2 to 20% by weight, based on all the structural units (100% by weight) of the acrylic copolymer. More preferably, it is 0.3-10 mass%, More preferably, it is 0.5-5 mass%.

In the present invention, from the viewpoint of reducing the acid value of the adhesive composition, the content of the structural unit derived from the carboxy group-containing monomer is preferably as small as possible in the structure of the acrylic copolymer. It is more preferable not to contain the structural unit derived from the containing monomer.
The content of the structural unit derived from the carboxy group-containing monomer is preferably 2.0% by mass or less, more preferably 1.0% by mass or less, with respect to all the structural units (100% by mass) of the acrylic copolymer. More preferably, it is 0.1% by mass or less, and still more preferably 0.0% by mass.

In addition, the said acrylic copolymer may have the structural unit derived from other monomers other than monomer (a1 ')-(a3').
Other monomers include, for example, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) ) (Meth) acrylate having a cyclic structure such as acrylate and imide (meth) acrylate, vinyl acetate, acrylonitrile, styrene and the like.

  In addition, the total content of the structural units (a1), (a2) and (a3) is preferably 80 to 100% by mass, and more preferably based on all the structural units (100% by mass) of the acrylic copolymer. Is 90 to 100% by mass, more preferably 95 to 100% by mass, and still more preferably 98 to 100% by mass.

(Urethane resin)
The urethane resin used in one embodiment of the present invention is not particularly limited as long as it is a polymer having at least one of a urethane bond and a urea bond in at least one of a main chain and a side chain.
As a specific urethane-based resin, for example, a chain extender is further added to the urethane-based prepolymer (U1) obtained by reacting a polyol and a polyvalent isocyanate compound, or the urethane-based prepolymer (U1). Examples thereof include a urethane polymer (U2) obtained by performing the chain extension reaction used.

  The mass average molecular weight (Mw) of the urethane-based resin is preferably 10,000 to 200,000, more preferably 12,000 to 150,000, still more preferably 15,000 to 100,000, and still more preferably 20,000 to 70,000.

Examples of the polyol used as a raw material for the urethane-based prepolymer (U1) include polyol compounds such as alkylene diol, polyether-type polyol, polyester-type polyol, and polycarbonate-type polyol. However, the polyol is not particularly limited. It may be a bifunctional diol or a trifunctional triol.
Among these polyols, diols are preferable from the viewpoints of availability, reactivity, and the like.

Examples of the diol include alkanediols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and 1,7-heptanediol, ethylene Examples thereof include alkylene glycols such as glycol, propylene glycol, diethylene glycol and dipropylene glycol, polyalkylene glycols such as polyethylene glycol, polypropylene glycol and polybutylene glycol, and polyoxyalkylene glycols such as polytetramethylene glycol. In addition, you may use these diols individually or in combination of 2 or more types.
Among these diols, when a reaction with a chain extender is further performed, a glycol having a mass average molecular weight of 1000 to 3000 is preferable from the viewpoint of suppressing gelation in the reaction.

Examples of the polyvalent isocyanate compound used as a raw material for the urethane prepolymer (U1) include aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates.
Examples of the aromatic polyisocyanate include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (2,4-TDI), 2 , 6-Tolylene diisocyanate (2,6-TDI), 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4 ' -Diphenyl ether diisocyanate, 4,4 ', 4 "-triphenylmethane triisocyanate, 1,4-tetramethylxylylene diisocyanate, 1,3-tetramethylxylylene diisocyanate and the like.
Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HMDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, and dodeca. Examples include methylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate.
Examples of the alicyclic polyisocyanate include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, Methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), 1,4-bis (isocyanatemethyl) cyclohexane, 1,4-bis (isocyanatemethyl) cyclohexane Etc.
These polyisocyanate compounds may be a trimethylolpropane adduct type modified product of the above polyisocyanate, a burette type modified product reacted with water, or an isocyanurate type modified product containing an isocyanurate ring.

  Among these polyvalent isocyanate compounds, 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (2,4-TDI), 2, from the viewpoint of obtaining a urethane polymer having excellent adhesive properties. One or more selected from 6-tolylene diisocyanate (2,6-TDI), hexamethylene diisocyanate (HMDI), 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI) and modified products thereof are preferable. From the viewpoint of weather resistance, at least one selected from HMDI, IPDI, and modified products thereof is more preferable.

  The isocyanate group content (NCO%) in the urethane-based prepolymer (U1) is preferably 0.5 to 12% by mass, more preferably 1 to 4% by mass in a value measured according to JIS K 1603. is there.

  As the chain extender, a compound having at least one of a hydroxyl group and an amino group or a compound having three or more of at least one of a hydroxyl group and an amino group is preferable.

The compound having at least one of a hydroxyl group and an amino group is preferably at least one compound selected from the group consisting of aliphatic diols, aliphatic diamines, alkanolamines, bisphenols, and aromatic diamines.
Examples of the aliphatic diol include alkanediols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and 1,7-heptanediol. And alkylene glycols such as ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol.
Examples of the aliphatic diamine include ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, and the like.
Examples of the alkanolamine include monoethanolamine, monopropanolamine, isopropanolamine and the like.
Examples of bisphenol include bisphenol A and the like.
Examples of the aromatic diamine include diphenylmethanediamine, tolylenediamine, xylylenediamine, and the like.

  Examples of the compound having three or more hydroxyl groups and amino groups include, for example, polyols such as trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, 1-amino-2,3-propanediol, 1-methyl Examples thereof include amino alcohols such as amino-2,3-propanediol and N- (2-hydroxypropylethanolamine), and ethylene oxide or propylene oxide adducts of tetramethylxylylenediamine.

(Polyisobutylene resin)
The polyisobutylene resin (hereinafter also referred to as “PIB resin”) used in one embodiment of the present invention is not particularly limited as long as it has a polyisobutylene skeleton in at least one of the main chain and the side chain.

  The mass average molecular weight (Mw) of the PIB resin is preferably 20,000 or more, more preferably 30,000 to 1,000,000, still more preferably 50,000 to 800,000, and still more preferably 70,000 to 600,000.

  Examples of the PIB resin include polyisobutylene, which is a homopolymer of isobutylene, a copolymer of isobutylene and isoprene, a copolymer of isobutylene and n-butene, a copolymer of isobutylene and butadiene, and these copolymers. Examples thereof include halogenated butyl rubber that has been brominated or chlorinated.

When the PIB-based resin is a copolymer, it is assumed that the structural unit composed of isobutylene is contained in the largest amount among all the structural units.
The content of the structural unit composed of isobutylene is preferably 80 to 100% by weight, more preferably 90 to 100% by weight, and still more preferably 95 to 100% by weight with respect to all the structural units (100% by weight) of the PIB resin. %.
These PIB resins may be used alone or in combination of two or more.

When using a PIB resin, it is preferable to use a PIB resin having a high mass average molecular weight and a PIB resin having a low mass average molecular weight, more specifically, a mass average molecular weight of 270,000 to 600,000. PIB resin (p1) (hereinafter also referred to as “PIB resin (p1)”) and PIB resin (p2) having a mass average molecular weight of 50,000 to 250,000 (hereinafter referred to as “PIB resin (p2)”). Are also preferably used in combination.
By using the PIB resin (p1) having a high mass average molecular weight, it is possible to improve the durability and weather resistance of the pressure-sensitive adhesive layer formed from the obtained pressure-sensitive adhesive composition, and also improve the pressure-sensitive adhesive force.
Further, by using the PIB resin (p2) having a low mass average molecular weight, it can be well compatible with the PIB resin (p1), and the PIB resin (p1) can be appropriately plasticized. The wettability of the layer to the adherend can be increased, and the adhesive properties, flexibility, and the like can be improved.

The mass average molecular weight (Mw) of the PIB resin (p1) is preferably 270,000 to 600,000, more preferably 290,000 to 480,000, still more preferably 310,000 to 450,000, and even more preferably 320,000 to 400,000. It is.
The mass average molecular weight (Mw) of the PIB resin (p2) is preferably 50,000 to 250,000, more preferably 80,000 to 230,000, still more preferably 140,000 to 220,000, and still more preferably 180,000 to 210,000. It is.

  The content ratio of the PIB resin (p2) to 100 parts by mass of the PIB resin (p1) is preferably 5 to 55 parts by mass, more preferably 6 to 40 parts by mass, still more preferably 7 to 30 parts by mass, and even more. Preferably it is 8-20 mass parts.

(Polyester resin)
The polyester resin used in one embodiment of the present invention is a copolymer obtained by a polycondensation reaction of an acid component and a diol component or a polyol component, and includes a modified product of the copolymer.
The polycondensation reaction is performed by a general polyesterification reaction such as a direct esterification method or a transesterification method.
The form of copolymerization of the polyester resin is not particularly limited, and the polyester resin may be any of a block copolymer, a random copolymer, and a graft copolymer. Moreover, the said polyester-type resin may use individually or in combination of 2 or more types.

  Examples of the acid component include terephthalic acid, isophthalic acid, phthalic anhydride, α-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid or esters thereof, pimelic acid, suberic acid, and azelain. Aliphatic dicarboxylic acids such as acid, sebacic acid, undecylene acid, dodecanedicarboxylic acid or esters thereof; and alicyclic dicarboxylic acids such as 1,4-cyclohexahydrophthalic anhydride.

  Examples of the diol component or polyol component include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, , 6-hexanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol, 3-methylpentanediol, 2,2,3-trimethylpentanediol, diethylene glycol, triethylene glycol, dipropylene glycol, etc. Aliphatic glycol, 1,4-cyclohexanediol, alicyclic glycol such as 1,4-cyclohexanedimethanol, and aromatic glycol such as bisphenol A.

(Polyolefin resin)
The polyolefin resin used in one embodiment of the present invention is not particularly limited as long as it is a polymer having a structural unit derived from an olefin compound such as ethylene or propylene.
When the polyolefin resin is a copolymer, the form of copolymerization is not particularly limited, and the polyolefin resin may be any of a block copolymer, a random copolymer, and a graft copolymer. May be. The polyolefin resin may be used alone or in combination of two or more.

  Specific polyolefin resins include, for example, polyethylenes such as low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene, polypropylene, copolymers of ethylene and propylene, ethylene and other α- Copolymers of olefins, copolymers of propylene and other α-olefins, copolymers of ethylene, propylene and other α-olefins, copolymers of ethylene and other ethylenically unsaturated monomers Examples thereof include ethylene (ethylene-vinyl acetate copolymer, ethylene-alkyl (meth) acrylate copolymer) and the like.

Examples of the α-olefin include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, 4-methyl-1-hexene and the like.
Examples of the ethylenically unsaturated monomer include vinyl acetate, alkyl (meth) acrylate, vinyl alcohol, and the like.

  Among these polyolefin resins, polypropylene resins containing a structural unit derived from propylene such as polypropylene, a copolymer of ethylene and propylene, and a copolymer of propylene and another α-olefin are preferable.

[Carbon filler]
The pressure-sensitive adhesive composition, which is a material for forming the pressure-sensitive adhesive layer, contains a carbon-based filler having an average aspect ratio of 3.0 or more together with a pressure-sensitive adhesive resin.
By using a pressure-sensitive adhesive composition containing a carbon-based filler having an average aspect ratio of 3.0 or more as a material for forming the pressure-sensitive adhesive layer, the carbon-based fillers are appropriately aggregated and formed in the process of forming the pressure-sensitive adhesive layer. In the pressure-sensitive adhesive layer, a network-like network is considered to be formed by the carbon-based filler. Since the network of the carbon-based filler is uniformly distributed in the pressure-sensitive adhesive layer, the surface resistivity of the pressure-sensitive adhesive layer is significantly reduced even if the content of the carbon-based filler is small. Presumed to be.

If the average aspect ratio of the carbon-based filler is less than 3.0, it is difficult to form a network network with the carbon-based filler in the formed adhesive layer, and the effect of reducing the surface resistivity is sufficiently exhibited. Not.
Therefore, the average aspect ratio of the carbon-based filler is preferably 5.0 or more, more preferably 10 or more, more preferably 50 or more, still more preferably 100 or more, still more preferably 130 or more, and excessively From the viewpoint of suppressing aggregation and non-uniform dispersion, it is preferably 10,000 or less, more preferably 2000 or less, still more preferably 1000 or less, and still more preferably 400 or less.

In the present invention, the “aspect ratio of the carbon-based filler” is the ratio of the length (H) of the long side to the length (L) of the short side of the target carbon-based filler [(H) / (L)]. It is a value calculated from
The length (H) of the long side of the carbon-based filler means the length in the longitudinal direction of the target carbon-based filler. In actual measurement, the two farthest points of the target carbon-based filler are used. The distance may be “long side length (H)”.
On the other hand, the length (L) of the short side of the carbon-based filler is such that the cross section is a circle or an ellipse when cut perpendicularly to the tangential direction at an arbitrary point of the target carbon-based filler. For example, if the cross section is a polygon, it means the diameter of the circumscribed circle of the polygon.

  The average length (H) of the long side of the carbon filler is preferably 0.01 to 2000 μm, more preferably 0.1 to 1000 μm, still more preferably 0.3 to 500 μm, still more preferably 0.5. ˜100 μm.

  The average short side length (L) of the carbon-based filler is preferably 1 to 1000 nm, more preferably 2 to 750 nm, more preferably 3 to 500 nm, still more preferably 5 to 100 nm, and still more preferably 7 to 50 nm.

  In the invention, “long side length (H)”, “short side length (L)” and “aspect ratio” of 10 arbitrarily selected carbon-based fillers were measured, and the average of these values was measured. The values can also be regarded as “average of long side length (H)”, “average of short side length (L)”, and “average aspect ratio”, respectively.

The shape of the carbon-based filler is not particularly limited as long as the carbon-based filler can be uniformly dispersed in the pressure-sensitive adhesive layer, but a columnar shape, a cylindrical shape, a weight shape, a fiber shape, and a combination thereof. The shape is preferably a columnar shape, a cylindrical shape, a fibrous shape, and a shape obtained by combining these shapes.
From the above viewpoint, the carbon-based filler is preferably a carbon-based filler having a shape formed by a fibrous material in which a plurality of single yarns are intertwined, such as wool, and a fiber in which a plurality of single yarns are intertwined. A cylindrical carbon-based filler formed of a shape is more preferable.

Examples of the carbon-based filler include conductive fillers containing carbon atoms, and specific examples include carbon nanomaterials, carbon black, milled carbon fiber, and graphite.
Among these, carbon nanomaterials are preferable from the viewpoints of reducing the surface resistivity of the formed pressure-sensitive adhesive layer and improving the adhesive strength.
The carbon nanomaterial is composed of a substance including a graphite sheet having a six-membered ring arrangement as a main structure, but the graphite structure may contain atoms other than carbon atoms such as boron atoms and nitrogen atoms. The carbon nanomaterial may be in a form containing another substance, and the carbon nanomaterial may be in a form modified with another conductive substance.

Examples of the carbon nanomaterial include carbon nanotube (CNT), carbon nanofiber, carbon nanohorn, carbon nanocone, fullerene, and the like, and carbon nanotube is preferable.
The carbon nanotube is a cylindrical carbon polyhedron having a structure in which a graphite (graphite) sheet mainly having a carbon 6-membered ring structure is closed in a cylindrical shape.
The carbon nanotube includes a single-walled carbon nanotube having a structure in which a single-layer graphite sheet is closed in a cylindrical shape, a double-walled carbon nanotube having a structure in which a two-layer graphite sheet is closed in a cylindrical shape, and a three-layered graphite sheet There are multi-walled carbon nanotubes having a multi-layer structure closed concentrically as described above, and any two or more of these can be used in combination.

Content of the carbon-type filler in an adhesive composition is 0.01-20 mass% with respect to the whole quantity (100 mass%) of the active ingredient in the said adhesive composition, Preferably 0.05- It is 10 mass%, More preferably, it is 0.10-7 mass%, More preferably, it is 0.20-5 mass%, More preferably, it is 0.30-3.5 mass%.
When the content of the carbon-based filler is less than 0.01% by mass, it is difficult to form a network network with the carbon-based filler in the formed pressure-sensitive adhesive layer, and the effect of reducing the surface resistivity is not sufficiently exhibited. .
On the other hand, when the content of the carbon-based filler exceeds 20% by mass, it is difficult to obtain an earth label having sufficient adhesive strength. Further, even if the content is increased, the effect of reducing the surface resistivity is not so much manifested. That is, by increasing the content of the carbon-based filler, it becomes easier to form micro-sized aggregates, and the presence of the aggregates obstructs the formation of a network network by the carbon-based filler. Guessed.

  Moreover, as a content rate of the carbon-type filler with respect to 100 mass parts of adhesive resin in an adhesive composition, from the said viewpoint, Preferably it is 0.01-20 mass parts, More preferably, 0.05-15 mass parts, More preferably, it is 0.1-10 mass parts, More preferably, it is 0.3-7 mass parts, More preferably, it is 0.5-4.5 mass parts, More preferably, it is 0.7-3.8 mass parts. .

[Oligomer component]
The adhesive composition used in the present invention preferably contains an oligomer component having a mass average molecular weight of less than 10,000 for the purpose of improving the flexibility and compatibility of the adhesive resin.
Examples of the oligomer component include acrylic oligomers, urethane oligomers, polyisobutylene oligomers, polyester oligomers, and polyolefin oligomers.
These oligomer components may be used alone or in combination of two or more.
In one embodiment of the present invention, it is preferable to include an oligomer of the same type (system) as the adhesive resin.

  The mass average molecular weight of the oligomer component is preferably less than 10,000, more preferably 1000 to 8000, and still more preferably 5000 to 7000.

  The content of the oligomer component is preferably 0.5 to 100 parts by mass of the adhesive resin from the viewpoint of improving flexibility and compatibility, and from the viewpoint of improving the conductivity of the pressure-sensitive adhesive layer to be formed. 40 parts by mass, more preferably 1.0-30 parts by mass, more preferably 1.5-20 parts by mass, still more preferably 2.0-10 parts by mass, and even more preferably 2.5-7.5 parts by mass. It is.

[Tackifier]
The adhesive composition used in the present invention preferably further contains a tackifier from the viewpoint of further improving the adhesive strength.
Examples of tackifiers include rosin resins such as rosin resins, rosin phenol resins, and ester compounds thereof; hydrogenated rosin resins obtained by hydrogenating these rosin resins; terpene resins, terpene phenol resins, aromatic modified terpenes Terpene resins such as pentene resins; hydrogenated terpene resins obtained by hydrogenating these terpene resins; copolymerization of C5 fractions such as pentene, isoprene, piperine, 1.3-pentadiene produced by thermal decomposition of petroleum naphtha C5 petroleum resin obtained and hydrogenated petroleum resin of this C5 petroleum resin; C9 fractions such as indene, vinyltoluene, α-methylstyrene, β-methylstyrene produced by thermal decomposition of petroleum naphtha are copolymerized And a C9 petroleum resin obtained by hydrogenation and a hydrogenated petroleum resin of the C9 petroleum resin.

The softening point of the tackifier is preferably 60 to 170 ° C, more preferably 75 to 150 ° C, still more preferably 85 to 140 ° C, and still more preferably 90 to 135 ° C, from the viewpoint of improving the adhesive strength.
In addition, the value of the softening point of the tackifier is a value measured according to JIS K2531.

The content of the tackifier is preferably 1 to 50 parts by mass, more preferably 1.5 to 40 parts by mass, still more preferably 2 to 30 parts by mass, and still more preferably 100 parts by mass of the adhesive resin. 3 to 20 parts by mass.
If content of a tackifier is 1 mass part or more, adhesive force can be improved further with respect to the adhesive composition obtained.
On the other hand, if the content of the tackifier is 50 parts by mass or less, sufficient flexibility can be imparted to the adhesive layer formed from the obtained adhesive composition. In addition, the surface resistivity of the pressure-sensitive adhesive layer can be adjusted to be low.

[Crosslinking agent]
The pressure-sensitive adhesive composition used in the present invention preferably further contains a tackifier from the viewpoint of further improving the pressure-sensitive adhesive force and holding power.
In particular, when the adhesive resin contains the above-mentioned acrylic resin (particularly, the above-mentioned acrylic copolymer having a functional group), from the viewpoint of improving the adhesive strength of the formed adhesive layer, a crosslinking agent. It is preferable to contain.

Examples of the crosslinking agent include isocyanate-based crosslinking agents such as tolylene diisocyanate, hexamethylene diisocyanate, and adducts thereof; epoxy-based crosslinking agents such as ethylene glycol glycidyl ether; hexa [1- (2-methyl) -aziridinyl ] Aziridine type cross-linking agents such as triphosphatotriazine; Chelate type cross-linking agents such as aluminum chelate;
These crosslinking agents may be used alone or in combination of two or more.
Among these, an isocyanate-based crosslinking agent is preferable from the viewpoint of increasing cohesive force and improving adhesive force.

  The content of the crosslinking agent is preferably 0.01 to 15 parts by mass, more preferably 0.05 to 10 parts by mass, and still more preferably 0.1 to 7.0 parts by mass with respect to 100 parts by mass of the adhesive resin. More preferably, it is 0.2-4.0 mass parts.

[Other additives]
The pressure-sensitive adhesive composition used in the present invention may further contain other additives as long as the effects of the present invention are not impaired.
Other additives include, for example, antioxidants, ultraviolet absorbers, curing accelerators (catalysts), light stabilizers, resin stabilizers, fillers, pigments, extenders, infrared absorbers, near infrared absorbers, antiseptics -Antifungal agent, rust preventive agent, plasticizer, high boiling point solvent and the like.
These additives may be used alone or in combination of two or more.

<Peeling sheet>
The release sheet used in the present invention is preferably a non-silicone release sheet.
As the release sheet, a release sheet that has been subjected to a double-sided release process, a release sheet that has been subjected to a single-sided release process, or the like is used, and examples include a release sheet in which a release agent is applied to a base for the release sheet.

  Examples of the base material for the release sheet include paper base materials such as glassine paper, coated paper, and high-quality paper, laminated paper obtained by laminating a thermoplastic resin such as polyethylene on these paper base materials, or polyethylene terephthalate resin, polybutylene. Examples thereof include polyester resin films such as terephthalate resin and polyethylene naphthalate resin, and plastic films such as polyolefin resin films such as polypropylene resin and polyethylene resin.

  The release agent is not particularly limited as long as it is a non-silicone release agent. For example, rubber elastomers such as olefin resins, isoprene resins, butadiene resins, long chain alkyl resins, alkyd resins, fluorine resins, etc. Examples thereof include a release agent containing a non-silicone resin.

  The thickness of the release sheet is preferably 10 to 200 μm, more preferably 25 to 150 μm.

<Primer layer>
The ground label of this invention may provide a primer layer further between a base material and an adhesive layer from a viewpoint of improving the adhesiveness of a base material and an adhesive layer.
The primer layer can be formed from a primer layer forming composition containing a resin component.
Examples of the resin component include acrylic resins, acrylic-modified polyolefin resins, chlorinated polyolefin resins, vinyl chloride-vinyl acetate copolymers, urethane resins, polyester resins, polyamide resins, rubber resins, and the like.
The primer layer forming composition may further contain general-purpose additives such as a filler, a plasticizer, a crosslinking agent, a tackifier, an antioxidant, and an ultraviolet absorber.

  The thickness of the primer layer is preferably 10 to 2000 nm, more preferably 20 to 1000 nm, and still more preferably 30 to 500 nm.

<Coat layer for printing>
The ground label of the present invention may further have a coating layer for printing printed on the surface of the substrate opposite to the side where the pressure-sensitive adhesive layer is laminated.
The coating layer for printing can be formed from a composition for forming a coating layer for printing that contains a resin component.
Examples of the resin component include acrylic resins, styrene resins, polyester urethane resins, polyester resins, polyurethane resins, polyol resins, polyvinyl alcohol, polyvinyl pyrrolidone, cellulose derivatives, acetate derivatives, polyvinyl chloride resins. , Polyimide resins, latex resins and the like.
In addition, the coating layer forming composition for printing and printing further includes general-purpose pigments, colorants, etc., damping materials, plasticizers, surfactants, dispersants, freeze-melt stabilizers, neutralizers, thickeners, General-purpose additives such as wetting agents, antifoaming agents, slip agents, rust inhibitors, antistatic agents, preservatives, antioxidants, and UV absorbers may be included.

  The thickness of the coating layer for printing is preferably 10 to 2000 nm, more preferably 30 to 600 nm, and still more preferably 50 to 200 nm.

[Manufacturing method of earth labels for attaching electronic components]
Although there is no restriction | limiting in particular as a manufacturing method of the earth label for electronic component sticking of this invention, The method which has the following processes (1)-(3) is preferable.
Step (1): A step of preparing a carbon-based filler dispersion.
Step (2): A step of preparing a pressure-sensitive adhesive composition by mixing the carbon-based filler dispersion obtained in step (1) and a pressure-sensitive adhesive resin.
-Process (3): The process of forming an adhesive layer using the adhesive composition obtained at the process (2).
As mentioned above, after preparing the dispersion liquid of a carbon-type filler, it can mix with adhesive resin etc. in a low-viscosity state by mixing with adhesive resin and preparing an adhesive composition. As a result, the carbon-based fillers are close to each other and moderately easily aggregate (to the extent that micro-sized aggregates are not formed), and a network network of carbon-based fillers is formed in the formed adhesive layer. It becomes easy.
Hereinafter, steps (1) to (3) will be described.

<Step (1)>
Water or an organic solvent can be used as the solvent used for preparing the carbon-based filler dispersion, but an organic solvent is preferred.
Examples of the organic solvent used in the preparation of the carbon filler dispersion include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, 1-propanol, isopropyl alcohol, dimethylformamide, N- Examples include methyl pyrrolidone and dimethyl sulfoxide.
These organic solvents may be used alone or in combination of two or more.
Among these, at least one selected from methyl ethyl ketone, ethyl acetate, toluene, and isopropyl alcohol is preferable, and at least one selected from ethyl acetate and isopropyl alcohol is more preferable.

  In this step, after adding the carbon-based filler to the solvent, it is preferable to prepare a carbon-based filler dispersion by a dispersion method using a bead mill, a dispersion method using ultrasonic waves, or the like.

In a dispersion method using a bead mill, it is preferable to prepare a dispersion under the following conditions.
-Bead diameter: Preferably it is 0.2-1.0 mm, More preferably, it is 0.3-0.9 mm, More preferably, it is 0.4-0.8 mm.
-Filling ratio: Preferably it is 50 to 95%, More preferably, it is 60 to 95%, More preferably, it is 70 to 90%.
-Peripheral speed: Preferably it is 1-20 m / s, More preferably, it is 3-15 m / s, More preferably, it is 5-12 m / s.
Treatment time: preferably 10 minutes to 5 hours, more preferably 30 minutes to 4 hours, and even more preferably 1 hour to 3 hours.

In the dispersion method using ultrasonic waves, it is preferable to prepare a dispersion under the following conditions.
-Ultrasonic amplitude: preferably 1 to 50 [mu] m, more preferably 5 to 45 [mu] m, still more preferably 10 to 40 [mu] m.
Treatment time: preferably 1 minute to 60 minutes, more preferably 5 minutes to 45 minutes, and even more preferably 10 minutes to 30 minutes.

  The solid content concentration of the carbon-based filler dispersion is preferably 0.01 to 60% by mass, more preferably 0.05 to 10% by mass, and still more preferably 0.1 to 3% by mass.

<Step (2)>
In this step, the carbon-based filler dispersion obtained in step (1) is mixed with the adhesive resin and the above-mentioned additives to prepare an adhesive composition.
In this step, the adhesive composition may be prepared by manual stirring, or the adhesive composition may be prepared using a stirrer.

Moreover, in this process, when mixing the dispersion liquid of a carbon-type filler, adhesive resin, and an additive, it is good also as the form of the solution of an adhesive composition, adding an organic solvent and diluting.
Examples of the organic solvent used for preparing the adhesive composition include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, 1-propanol, isopropyl alcohol, dimethylformamide, and N-methylpyrrolidone. And dimethyl sulfoxide.
These organic solvents may be used alone or in combination of two or more.
Among these, at least one selected from methyl ethyl ketone, ethyl acetate, toluene, and isopropyl alcohol is preferable, and at least one selected from ethyl acetate and isopropyl alcohol is more preferable.
As these organic solvents, the organic solvent used in the synthesis of the adhesive resin or the organic solvent used when the carbon-based filler is prepared in the form of a dispersion may be used as it is, or the obtained adhesive composition. One or more organic solvents other than the organic solvent used for the synthesis of the adhesive resin or the carbon-based filler dispersion may be added so that the solution of the product can be uniformly applied.
As solid content concentration of the solution of an adhesive composition, Preferably it is 5-60 mass%, More preferably, it is 7-45 mass%, More preferably, it is 10-30 mass%.

<Step (3)>
In this step, the pressure-sensitive adhesive layer is formed using the pressure-sensitive adhesive composition obtained in step (2).
The pressure-sensitive adhesive layer can be formed by applying the pressure-sensitive adhesive composition obtained in step (2) on a substrate or a release sheet to form a coating film, and then drying the coating film.
Examples of the method for applying the adhesive composition include spin coating, spray coating, bar coating, knife coating, roll knife coating, roll coating, blade coating, die coating, and gravure coating. It is done.

As drying conditions of a coating film, it is preferable to dry by drying temperature 25-150 degreeC (preferably 50-120 degreeC) for 10 second-50 minutes (preferably 30 second-30 minutes).
After drying, the remaining release sheet or substrate is laminated on the surface of the formed pressure-sensitive adhesive layer, whereby the electronic component pasting earth label of the present invention can be produced.

[Physical properties of earth labels for attaching electronic components]
The adhesive strength of the ground label for attaching an electronic component of the present invention is preferably 5.0 N / 25 mm or more, more preferably 10.0 N / 25 mm or more, still more preferably 14.0 N / 25 mm or more, and preferably 50.0 N / 25 mm or less, more preferably 40.0 N / 25 mm or less.
In addition, the value of the said adhesive force is a value measured by the method as described in an Example.

The surface measured from the surface side of the pressure-sensitive adhesive layer exposed after removing the release sheet after leaving the ground label for attaching electronic parts of the present invention in an environment of 23 ° C. and 50% RH (relative humidity) for 1 week. The resistivity is preferably 1.00 × 10 ⁸ Ω / □ or less, more preferably 1.00 × 10 ⁷ Ω / □ or less, still more preferably 1.00 × 10 ⁶ Ω / □ or less, and still more preferably. It is 1.00 × 10 ⁵ Ω / □ or less.
In addition, the value of surface resistivity is a value measured by the method as described in an Example.

  The physical property value of each component used and the acid value of the prepared adhesive composition were measured by the methods described below.

<Aspect ratio of carbon filler>
Using a scanning electron microscope (manufactured by Hitachi High-Technologies Corporation, product name “S-4700”), 10 randomly extracted carbon-based fillers were observed, and each “long side length (H ) ”And“ short side length (L) ”were measured, and“ aspect ratio (H / L) ”was calculated. Then, the 10 average values were taken as “average of long side length (H)”, “average of short side length (L)”, and “average aspect ratio” of the target carbon-based filler.

<Mass average molecular weight (Mw)>
Using a gel permeation chromatograph device (product name “HLC-8020” manufactured by Tosoh Corporation), the value measured under the following conditions and measured in terms of standard polystyrene was used.
(Measurement condition)
Column: “TSK guard column HXL-H”, “TSK gel GMHXL (× 2)”, “TSK gel G2000HXL” (both manufactured by Tosoh Corporation), column temperature: 40 ° C.
・ Developing solvent: Tetrahydrofuran ・ Flow rate: 1.0 mL / min

<Silicon atom concentration in each layer constituting the earth label>
Using the XPS measurement analyzer (product name “PHI Quantera SXM” manufactured by ULVAC-PHI Co., Ltd.), under the following conditions, in each layer of the base material, pressure-sensitive adhesive layer, and release sheet constituting the ground label, Each atom concentration of carbon atom, oxygen atom, and silicon atom measured by XPS was measured.
Then, the silicon atom concentration (atom%) was calculated with respect to the total of 100 atom% of the respective atom concentrations of the obtained carbon atom, oxygen atom, and silicon atom.
(Measurement condition)
・ X-ray source: Monochromatic AlKα
・ Output: 25W
・ Acceleration voltage: 15 kV
・ Beam diameter: 100μm
-Photoelectron extraction angle: 45 °
Pulse energy: 112 eV (carbon atom, oxygen atom), 224 eV (silicon atom)
Step resolution: 0.1 eV (carbon atom, oxygen atom), 0.2 eV (silicon atom)
Measurement area: a circle of 100 μm diameter arbitrarily selected on the surface of each layer

<Acid value of adhesive composition>
In the following process for preparing the ground labels of Examples and Comparative Examples, 0.3 g (solid content) of the pressure-sensitive adhesive layer formed on the release sheet was weighed and collected, dissolved in toluene as a solvent, and solid A solution of an adhesive composition having a partial concentration of 1% by mass was prepared.
Next, after adding 2-3 drops of an alcohol solution of phenolphthalein as an indicator to the prepared adhesive composition solution, the solution was titrated with an alcohol solution of 0.1 N potassium hydroxide. The end point was when the solution turned red, and the acid value (unit: mgKOH / g) was calculated from the titration amount and sample mass at this time.

Production Example 1
(Preparation of dispersion of carbon filler (1))
As the carbon-based filler (1), “K-nanos 100P” (product name, manufactured by Korea Kumho Petrochemical Co., Ltd., cylindrical multi-walled carbon nanotube formed by a fibrous material in which a plurality of single yarns are intertwined, average aspect ratio ( H / L): 200, average length of long side (H): 2 μm, average length of short side (L): 10 nm).
The carbon-based filler (1) is added to ethyl acetate and dispersed for 150 minutes at a peripheral speed of 8 m / sec using a bead mill (bead diameter: 0.65 mm, filling rate: 85%). A dispersion of carbon-based filler (1) having a partial concentration of 0.3% by mass was prepared.

Production Example 2
(Preparation of dispersion of carbon filler (2))
As the carbon-based filler (2), “NC7000” (product name, manufactured by Nanosil Co., Ltd., cylindrical multi-walled carbon nanotube formed by a fibrous material in which a plurality of single yarns are intertwined, average aspect ratio (H / L): 200, average of long side length (H): 2 μm, average of short side length (L): 10 nm).
The carbon-based filler (2) is added to ethyl acetate, and ultrasonic vibration with an amplitude of 30 μm is applied using an ultrasonic disperser (manufactured by Sonic Technology Co., Ltd., product name “Ultrasonic Disperser for Testing GSD600AT”). This was applied for 15 minutes to prepare a dispersion of carbon-based filler (2) having a solid concentration of 0.3% by mass.

Examples 1-20, Comparative Examples 1-5
(1) Preparation of solution of adhesive composition For 100 parts by mass (solid content) of adhesive resin of the type shown in Table 1, dispersion of carbon-based filler having the types and solid content shown in Table 1, and various additions Agents (oligomer component, tackifier, cross-linking agent) were added. And it diluted with ethyl acetate and stirred, and the solution of the adhesive composition with a solid content concentration of 10 mass% was prepared.

(2) Production of earth label The release sheet and base material used are as follows.
Release sheet: non-silicone release sheet having a thickness of 50 μm, polyethylene terephthalate whose surface has been subjected to release treatment with a rubber release agent including 1,4-polybutadiene rubber (cis 1,4 bond content: 96.0%) (PET) film. Based on the above measurement method from the peel-treated surface, the silicon atom concentration is less than 0.2 atom% with respect to the total atom concentration of 100 atoms% of carbon atoms, oxygen atoms, and silicon atoms measured by XPS.
Base material: PET film having a thickness of 50 μm (trade name “Lumirror” manufactured by Toray Industries, Inc.). Based on the above measurement method, the silicon atom concentration is less than 0.2 atom% with respect to the total atom concentration of 100 atom% of carbon atom, oxygen atom, and silicon atom measured by XPS.

The prepared adhesive composition solution is applied onto the release-treated surface of the release sheet so that the thickness after drying is 20 μm to form a coating film, and the coating film is dried at 90 ° C. for 1 minute. And an adhesive layer was formed.
And the said base material was bonded together on the said said adhesive layer formed, and the earth label comprised from the base material / adhesive layer / release sheet was produced.

In any of the examples and comparative examples, before bonding the base material, each atom concentration of carbon atom, oxygen atom, and silicon atom by XPS was applied to the formed adhesive layer based on the measurement method. Was measured. And the silicon atom density | concentration with respect to a total of 100 atom% of these each atomic density | concentration was computed.
Moreover, 0.3 g (solid content) was extract | collected from the adhesive layer before bonding the said base material, and the acid value of the adhesive composition was measured based on the said method.
The obtained silicon atom concentration and acid value are shown in Table 1.

The details of the adhesive resin, the carbon-based filler dispersion, the oligomer component, the tackifier, and the crosslinking agent used in the solutions of the adhesive compositions of the examples and comparative examples shown in Table 1 are as follows. is there.
<Adhesive resin>
"Acrylic resin (1)": n-butyl acrylate (BA), methyl acrylate (MA), acryloylmorpholine (ACMO), and 2-hydroxyethyl acrylate (HEA), Acrylic resin (constituent unit ratio: BA / MA / ACMO / HEA = 80.0 / 5.0 / 14.0 / 1.0 (mass ratio)).
"Acrylic resin (2)": Mw of 600,000 obtained by copolymerizing n-butyl acrylate (BA), methyl acrylate (MA), acryloylmorpholine (ACMO), and 2-hydroxyethyl acrylate (HEA) Acrylic resin (constituent unit ratio: BA / MA / ACMO / HEA = 75.0 / 4.0 / 20.0 / 1.0 (mass ratio)).
"Acrylic resin (3)": Mw 700,000 acrylic resin (constituent unit ratio: 2EHA /) obtained by copolymerizing 2-ethylhexyl acrylate (2EHA), vinyl acetate (Vac), and acrylic acid (AAc) Vac / AAc = 75.0 / 22.5 / 2.5 (mass ratio)).
"Acrylic resin (4)": acrylic resin having a Mw of 600,000 obtained by copolymerizing n-butyl acrylate (BA) and acrylic acid (AAc) (constituent unit ratio: BA / AAc = 90.0 / 10) 0.0 (mass ratio)).
"Acrylic resin (5)": Mw 500,000 acrylic resin obtained by copolymerizing n-butyl acrylate (BA) and acrylic acid (AAc) (constituent unit ratio: BA / AAc = 80.0 / 20) 0.0 (mass ratio)).
"Acrylic resin (6)": Acrylic resin having a Mw of 500,000 obtained by copolymerizing n-butyl acrylate (BA) and acrylic acid (AAc) (constituent unit ratio: BA / AAc = 95.0 / 5) 0.0 (mass ratio)).

<Dispersion of carbon-based filler>
“CNT (1)”: A dispersion of carbon-based filler (1) prepared in Production Example 1.
“CNT (2)”: A dispersion of carbon-based filler (2) prepared in Production Example 2.
<Oligomer component>
"UP-1080": Toagosei Co., Ltd. product name "UP-1080", acrylic oligomer of Mw 6000.
<Tackifier>
“TF (1)”: manufactured by Yasuhara Chemical Co., Ltd., product name “YS Polystar G125”, softening point: 125 ° C., terpene phenol oligomer.
"TF (2)": manufactured by Yasuhara Chemical Co., Ltd., product name "YS Polyster TH130", softening point: 130 ° C, terpene phenol oligomer.
<Crosslinking agent>
"Crosslinking agent (1)": manufactured by Mitsui Chemicals, product name "Taketate D-110N", isocyanate crosslinking agent.
"Crosslinking agent (2)": Product name "M-5A" manufactured by Soken Chemical Co., Ltd., metal chelate crosslinking agent.
-"Crosslinking agent (3)": Tosoh Corporation product name "Coronate L", isocyanate type crosslinking agent.

  About the earth label for electronic component sticking produced in the Example and the Comparative Example, the adhesive strength, holding power, surface resistivity, the effect of suppressing the oxidative degradation of the adherend, and the printing / printing suitability were measured or evaluated by the following methods. did. These results are shown in Table 2.

(1) Adhesive strength Adhesive layer exposed by removing the release sheet from a test piece obtained by cutting the produced ground label into a size of 5 mm × 300 mm in an environment of 23 ° C. and 50% RH (relative humidity) A sample was attached to a stainless steel plate (SUS304, No. 360 polishing) as a test sample.
After standing for 24 hours in an environment of 23 ° C. and 50% RH, the adhesive strength of the earth label for attaching electronic components was measured at a pulling speed of 300 mm / min by a 180 ° peeling method in accordance with JIS Z0237: 2000. It was measured.

(2) Holding force About the test piece which cut the produced earth label into the magnitude | size of 5 mm x 300 mm, the adhesive layer which exposed by removing the peeling sheet in the environment of 23 degreeC and 50% RH (relative humidity) A sample was attached to a stainless steel plate (SUS304, No. 360 polishing) as a test sample. At the time of sticking, a roller having a weight of 2 kg was used and reciprocated five times to be pressed against a stainless steel plate.
After affixing to the stainless steel plate, it is allowed to stand for 20 minutes, then transferred to a constant temperature layer at a temperature of 40 ° C., a 1 kg weight is attached to the ground label in a vertical direction, and the ground label is placed in the constant temperature bath. The elapsed time (seconds) until complete peeling from the stainless steel plate was measured.
However, in Table 2, it is written as “NC” when the peeled off length is less than 0.1 mm even after 70000 seconds have elapsed.

(3) Surface resistivity A test piece obtained by cutting the produced ground label into a size of 20 mm × 40 mm was left to stand for one week in an environment of 23 ° C. and 50% RH (relative humidity). After standing, a low resistivity meter (manufactured by Mitsubishi Chemical Analytech Co., Ltd., product name “Loresta GP MCP-T610”) is used on the surface of the pressure-sensitive adhesive layer that is exposed by removing the release sheet from the test piece. The surface resistivity was measured according to JIS-K7194. The measurement was performed three times, and the average of these three measurement values was used as the surface resistivity of the adhesive layer of the target earth label.

(4) Effect of suppressing oxidative degradation of adherend A test sample was prepared by attaching a pressure-sensitive adhesive layer that was exposed by removing a release sheet of a test piece obtained by cutting a prepared ground label to 20 mm × 40 mm to a copper plate. . This test sample was allowed to stand for 1 week in a normal temperature environment of 23 ° C. and 50% RH (relative humidity) and in a high temperature and high humidity environment of 60 ° C. and 95% RH. After standing, remove the test piece from the copper plate, and visually observe the surface of the exposed copper plate for discoloration. Based on the following criteria, the oxidative deterioration of the adherend in a normal temperature environment and a high temperature and high humidity environment The inhibitory effect was evaluated.
A: Discoloration is not confirmed on the copper plate, and the effect of suppressing the oxidative deterioration of the adherend is excellent.
F: Discoloration is observed on the surface of the copper plate to which the test piece has been attached, and the effect of suppressing the oxidative deterioration of the adherend is poor.

(5) Printing / printing suitability This was carried out according to JIS L0849 (2004).
Specifically, first, using a thermal transfer printer (trade name “140XiIII” manufactured by Zebra Technology Co., Ltd.) and a thermal transfer ribbon (trade name “TR4070” manufactured by Dexerials Corporation), a base material (polyethylene terephthalate resin) produced. ) A barcode was printed on top.
Then, barcode reading evaluation was performed according to ANSI (American National Standards Institute) X3.182 (1990) standard Bar Code Quality Guideline using a barcode reading verification machine (RJS, product name “INSPECTOR 3000”).
The evaluation results were classified as follows according to the decodeability value. “Decodeability value” means the degree of ease of decoding, and is calculated for each character. The minimum value of each result is finally set as the decodability value of the entire symbol, and the higher the value, the more suitable for printing and printing. It can be said that it is excellent.
A: Decodeability value is 0.62 or more.
B: The decodability value is 0.50 or more and less than 0.62.
C: Decoding ability value is 0.37 or more and less than 0.50.
D: Decodeability value is 0.25 or more and less than 0.37.
E: Decodeability value is less than 0.25.

From the results shown in Table 2, the ground labels produced in Examples 1 to 20 have high adhesive strength and holding power, low surface resistivity, excellent effect of suppressing oxidative degradation of the adherend, and printing / printing suitability. Was good.
On the other hand, the ground label produced in Comparative Example 1 does not contain a carbon-based filler in the pressure-sensitive adhesive layer, and thus has a high surface resistivity and is unsuitable for use as a ground label.
In addition, the ground labels produced in Comparative Examples 2 to 5 were poor in the effect of suppressing the oxidative deterioration of the adherend, and in particular, the ground label of Comparative Example 4 also showed a decrease in adhesive strength.

The ground label for affixing electronic parts of the present invention has high adhesive strength, is excellent in electrical conductivity, has a high effect of suppressing oxidative deterioration of the adherend, and has good printing and printing suitability.
Therefore, the electronic component pasting earth label of the present invention is, for example, an electronic component used for joining an electronic device such as a computer or a communication device, an electromagnetic shielding material for a storage container, a grounding wire such as an electric component, or a fire prevention material. It can be suitably used as a grounding label for sticking.
The ground label for attaching electronic parts of the present invention has a low silicon atom concentration, and the content of the silicone compound is adjusted. Therefore, even if the ground label is used for attaching HDDs, it is possible to effectively suppress the formation of deposits made of silicone compounds that cause a decrease in HDD reliability, thus improving HDD reliability. Can be made.
Therefore, the ground label for attaching an electronic component of the present invention is more suitable as an earth label for attaching an HDD component used for attaching a component in a hard disk.

DESCRIPTION OF SYMBOLS 1 Ground label for electronic component sticking 11 Base material 11a Surface 12 Adhesive layer 21 Electronic component 22 Housing

Claims (5)

On the base material, together with the adhesive resin, formed from an adhesive composition containing 0.01 to 20% by mass of a carbon-based filler having an average aspect ratio of 3.0 or more and an acid value of 5.0 mgKOH / g or less. An earth label in which an adhesive layer and a release sheet are laminated in order,
In each layer constituting the earth label, the silicon atom concentration is less than 0.5 atom% with respect to a total of 100 atom% of each atom concentration of carbon atom, oxygen atom, and silicon atom measured by X-ray photoelectric spectroscopy (XPS). An earth label for attaching electronic components.   The said adhesive resin contains the acryl-type copolymer which has the structural unit (a1) derived from alkyl (meth) acrylate, and the structural unit (a2) derived from (meth) acryloylmorpholine. Earth label for attaching electronic parts.   The earth label for electronic component sticking of Claim 1 or 2 whose said adhesive resin is adhesive resin which does not have a carboxy group.   The electronic component affixing according to any one of claims 1 to 3, which has a configuration in which a coating layer for print printing is further laminated on a surface opposite to the side on which the pressure-sensitive adhesive layer of the substrate is laminated. Earth label.   The ground label for electronic component sticking as described in any one of Claims 1-4 used for sticking of the component in a hard disk.